The invention relates to fuel supply systems for fuel injected internal combustion engines, and particularly to a device for purging gases, including air and vapor, from the system. The purging device may be used in combination with the fuel injection systems shown in my co-pending application Ser. No. 808,135, filed Dec. 12, 1985, and U.S. Pat. No. 4,699,109.
In a fuel injection system, a fuel pump draws fuel from a fuel tank and delivers pressurized fuel through a pressure line to one or more fuel injectors. At initial start-up, the high pressure fuel line and the fuel pump may be devoid of fuel, particularly after a long lay-off or when the fuel system has run dry. The fuel injection system may have difficulty in pumping such air and/or vapor, and in any event requires longer engine cranking and difficult starting, as well as poor initial performance.
The present invention provides a simple and effective device for purging gases from the high pressure fuel line.